I am trying to encrypt and decrypt the file by using android open ssl. Below sharing the JNI wrapper for the same.
JNIEXPORT jbyteArray JNICALL
Java_com_example_MainActivity_AESencrypt( JNIEnv* env, jobject thiz, jint
length, jbyteArray jarrByte)
{
unsigned char plaintext[AES_BLOCK_SIZE * 4];
unsigned char ciphertext[AES_BLOCK_SIZE * 4];
unsigned char checktext[AES_BLOCK_SIZE * 4];
const unsigned char userKey[AES_BLOCK_SIZE * 4] = "123456";
const int bits = 128;
AES_KEY keyin = { { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0,
0,
0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, }, 12 };
AES_KEY *key = &keyin;
jbyte* pJbyte = env->GetByteArrayElements(jarrByte, NULL);
if(pJbyte!=NULL){
memcpy(plaintext, pJbyte, length);
env->ReleaseByteArrayElements(jarrByte, pJbyte, JNI_ABORT);
}
unsigned char* beforeEncrypt = &plaintext[0];
unsigned char* afterEncrypt = &ciphertext[0];
AES_set_encrypt_key(userKey, bits, key);
AES_encrypt(beforeEncrypt, afterEncrypt, key);
jbyteArray jarrRet = env->NewByteArray(strlen((char*) ciphertext));
env->SetByteArrayRegion(jarrRet, 0, strlen((char*) ciphertext), (jbyte *) ciphertext);
return jarrRet;
}
JNIEXPORT jbyteArray JNICALL
Java_com_example_MainActivity_AESdecrypt( JNIEnv* env, jobject thiz, jint
length, jbyteArray jarrByte)
{
unsigned char encryptText[AES_BLOCK_SIZE * 4];
unsigned char ciphertext[AES_BLOCK_SIZE * 4];
unsigned char checktext[AES_BLOCK_SIZE * 4];
const unsigned char userKey[AES_BLOCK_SIZE * 4] = "123456";
const int bits = 128;
AES_KEY keyin = { { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0,
0,
0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, }, 12 };
AES_KEY *key = &keyin;
jbyte* pJbyte = env->GetByteArrayElements(jarrByte, NULL);
if(pJbyte!=NULL){
memcpy(encryptText, pJbyte, length);
env->ReleaseByteArrayElements(jarrByte, pJbyte, JNI_ABORT);
}
unsigned char* beforeDecrypt = &encryptText[0];
unsigned char* afterDecrypt = &ciphertext[0];
AES_set_decrypt_key(userKey, bits, key);
AES_decrypt(beforeDecrypt, afterDecrypt, key);
jbyteArray jarrRet = env->NewByteArray(strlen((char*) ciphertext));
env->SetByteArrayRegion(jarrRet, 0, strlen((char*) ciphertext), (jbyte *) ciphertext);
return jarrRet;
}
I am calling JNI methods as below.
Mainactivity.java :
public void jni_encryption_and_decryption {
// reads the file and converts into bytes
plainTextBytes = getBytesFromInputFile();
len = plainTextBytes.length;
// encrypts the plain text and returns the encrypted bytes
byte[] encryptedByte = AESencrypt(len, plainTextBytes);
String encryptString = new String(encryptedByte);
encrypt.setText(encryptString);
len = encryptedByte.length;
// decrypts encrypted bytes and returns the decrypted bytes
decryptedByte = AESdecrypt(len, encryptedByte);
String decryptString = new String(decryptedByte);
decrypt.setText(decryptString);
}
Encryption is working fine but while decryption, junk is coming and also If the file contains more plain text, it is not decryting complete plain text.
Input from File: This is an android openssl encryption and decryption demo
Encryption Text: �UZ�L\n�c�������a��[���ܰ�h�ܰ�ܰ0_��
Decryption Text: This is an andro�ܰ���0_�!
I also shared bytes before and after encryption. Till 15th index bytes are same. after that bytes are found not same.
What is wrong in Jni Wrapper? Am I missing anything? Please help.
JNIEXPORT jbyteArray JNICALL
Java_com_example_MainActivity_doEncryption(jbyteArray data_plaintext, int
plaintext_len, jbyteArray data_key,
jbyteArray data_iv, jbyteArray data_ciphertext)
{
unsigned char* key = (unsigned char*) data_key;
unsigned char* iv = (unsigned char*) data_iv;
unsigned char* plaintext = (unsigned char*) data_plaintext;
unsigned char* ciphertext = (unsigned char*) data_ciphertext;
EVP_CIPHER_CTX *ctx;
int len;
int ciphertext_len;
/* Create and initialise the context */
if(!(ctx = EVP_CIPHER_CTX_new())){
ERR_print_errors_fp(stderr);
abort();
}
/* Initialise the encryption operation. IMPORTANT - ensure you use a key
* and IV size appropriate for your cipher
* In this example we are using 256 bit AES (i.e. a 256 bit key). The
* IV size for *most* modes is the same as the block size. For AES this
* is 128 bits */
if(1 != EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv)){
ERR_print_errors_fp(stderr);
abort();
}
/* Provide the message to be encrypted, and obtain the encrypted output.
* EVP_EncryptUpdate can be called multiple times if necessary
*/
if(1 != EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len)){
ERR_print_errors_fp(stderr);
abort();
}
ciphertext_len = len;
/* Finalise the encryption. Further ciphertext bytes may be written at
* this stage.
*/
if(1 != EVP_EncryptFinal_ex(ctx, ciphertext + len, &len)){
ERR_print_errors_fp(stderr);
abort();
}
ciphertext_len += len;
/* Clean up */
EVP_CIPHER_CTX_free(ctx);
jbyteArray ciphertext_copy = (jbyteArray ) ciphertext;
return ciphertext_copy;
}
Below sharing the error details:
Error Details : * What went wrong: Execution failed for task ':app:externalNativeBuildDebug'.
Build command failed. Error while executing process C:\android\sdk\cmake\3.6.4111459\bin\cmake.exe with arguments {--build C:\Users\SampleJni\app.externalNativeBuild\cmake\debug\armeabi-v7a --target native-lib} [1/1] Linking CXX shared library ........\build\intermediates\cmake\debug\obj\armeabi-v7a\libnative-lib.so FAILED: cmd.exe /C "cd . && C:\android\sdk\ndk-bundle\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++.exe --target=armv7-none-linux-androideabi --gcc-toolchain=C:/android/sdk/ndk-bundle/toolchains/arm-linux-androideabi-4.9/prebuilt/windows-x86_64 --sysroot=C:/android/sdk/ndk-bundle/sysroot -fPIC -isystem C:/android/sdk/ndk-bundle/sysroot/usr/include/arm-linux-androideabi -D__ANDROID_API__=14 -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16 -fno-integrated-as -mthumb -Wa,--noexecstack -Wformat -Werror=format-security -O0 -fno-limit-debug-info -Wl,--exclude-libs,libgcc.a --sysroot C:/android/sdk/ndk-bundle/platforms/android-14/arch-arm -Wl,--build-id -Wl,--warn-shared-textrel -Wl,--fatal-warnings -Wl,--fix-cortex-a8 -Wl,--no-undefined -Wl,-z,noexecstack -Qunused-arguments -Wl,-z,relro -Wl,-z,now -shared -Wl,-soname,libnative-lib.so -o ........\build\intermediates\cmake\debug\obj\armeabi-v7a\libnative-lib.so CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o ../../../../openssl-armeabi-v7a/lib/libcrypto.a ../../../../openssl-armeabi-v7a/lib/libssl.a -llog -lm "C:/android/sdk/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/libs/armeabi-v7a/libgnustl_static.a" && cd ." ../../../../openssl-armeabi-v7a/lib/libcrypto.a(ui_openssl.o):ui_openssl.c:function read_string_inner: error: undefined reference to 'signal' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(ui_openssl.o):ui_openssl.c:function read_string_inner: error: undefined reference to 'tcsetattr' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(ui_openssl.o):ui_openssl.c:function read_string_inner: error: undefined reference to 'tcsetattr' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(ui_openssl.o):ui_openssl.c:function open_console: error: undefined reference to 'tcgetattr' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function zlib_stateful_expand_block: error: undefined reference to 'inflate' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function zlib_stateful_compress_block: error: undefined reference to 'deflate' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_free: error: undefined reference to 'inflateEnd' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_free: error: undefined reference to 'deflateEnd' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function zlib_stateful_finish: error: undefined reference to 'inflateEnd' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function zlib_stateful_finish: error: undefined reference to 'deflateEnd' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function zlib_stateful_init: error: undefined reference to 'inflateInit_' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function zlib_stateful_init: error: undefined reference to 'deflateInit_' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_ctrl: error: undefined reference to 'deflate' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_ctrl: error: undefined reference to 'zError' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_write: error: undefined reference to 'deflate' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_write: error: undefined reference to 'zError' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_write: error: undefined reference to 'deflateInit_' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_read: error: undefined reference to 'inflate' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_read: error: undefined reference to 'zError' ../../../../openssl-armeabi-v7a/lib/libcrypto.a(c_zlib.o):c_zlib.c:function bio_zlib_read: error: undefined reference to 'inflateInit_' clang++.exe: error: linker command failed with exit code 1 (use -v to see invocation) ninja: build stopped: subcommand failed.
